Field of the Invention
The present invention relates to a trim adjustment device mounted on an aircraft.
Description of the Related Art
An aircraft includes a trim adjustment device for setting a neutral position of a control surface controlling section before take-off or during flight according to the weight, the center of gravity, and distortion of the airframe (see, for example, Japanese Patent Laid-Open No. 6-321190.). Performing trim adjustments reduces the burden on a pilot who steers a control wheel, a control stick, and/or a control pedal of an aircraft that serve as control surface controlling sections.
Such a trim adjustment device includes a trim control switch provided on a control stick or a control panel, and in response to the operation of the trim control switch, the trim adjustment device outputs a designated value indicating a neutral position of a control surface controlling section. The designated value is displayed on a monitor screen in a pilot compartment as an angle of a control surface or a relative ratio in a trim control range. A pilot operates the trim control switch to increase or decrease the designated value, thereby adjusting the designated value to an appropriate value.
The trim control switch operates such that, while it is pressed, the designated value changes at a prescribed amount of change per unit time (a changeable rate). When a pilot performs a trim adjustment, the operator continuously presses the trim control switch to have the designated value reach the vicinity of a desired value, and then repeatedly presses it several times to adjust the designated value to the desired value.
It is assumed that the changeable rate of the trim control switch is 3.0 degrees per second, for example. In this case, when the trim control switch is pressed only for ¼ second, the value advances 0.75 degree. Thus, when the designated value is displayed on a monitor screen with a resolution of 0.1 degree, it is difficult to advance the value only by 0.1 degree from 6.0 degrees to 6.1 degrees. In other words, it is difficult to press the trim control switch for a time period corresponding to 0.1 degree. Thus, the trim adjustment involves advancing the designated value to exceed the desired value 6.1 and then excessively returning, which renders the operation more difficult and time consuming.
Thus, the object of the present invention is to improve the workability of trim adjustments.